Research On Preparation And Property Of Catalyst Used In Catalytic Wet Peroxide Oxidation Process Under Normal Temperature And Atmospheric Pressure

At present, the problem of high concentration organic acrylic wastewater treatment isrecognized at home and abroad.Acrylic wastewater has become a difficulty and hotspot in thefield of water treatment，because of its difficult biodegradation characteristics. Effectivemethods is to enhance the pretreatment of the waste water, improving wastewater’sbiochemical availability, then go through biochemical treatment to achieve emissionsstandards. Among various kinds of pretreatment method, catalytic wet peroxide oxidation isone of effective methods. The development of catalyst is the core of normal pressure andtemperature CWPO technology.This topic main research content is the preparation of CWPOcatalysts, Select the difficult degradable organic industrial wastewater--acrylic wastewater asan example, examining the catalytic activity of catalysts preparation.With activated carbon asthe carrier, this study selected transition metals as the active component, used nitrate dippingmethod, preparated monometallic catalyst, investigated catalytic properties of various metal,determined the active component and carrier of distribution of catalyst, and optimized thereaction conditions.Then added rare earth element Ce on modification to preparat multi-metalload type catalyst of CWPO technology that is used to treatment refractory organic acrylonwastewater. Through the continuous reaction，with acrylon wastewater removal rate of CODand the dissolubility of active component as an index, investigate catalyst’s catalytic activityand stability NPT CWPO process.The homemade catalysts were characterized by means ofBET, XRD and TEM.Experimental study has found that Fe, Mn, Cu, Ce the four metals as the active componentpreparation monometallic catalysts for the catalytic effect is good.The Co/AC is inefficiency. The metal impregnated activated carbon particles in the preparation of the mass concentrationof7.5%solution has the highest catalyst activity.The optimum calcination temperature ofMn/AC,Cu/AC,Fe/AC,Ce/AC is600℃,600℃,400℃and400℃.Represented byMn/AC catalyst at the same time, found the CWPO optimum reaction condition is that add2g catalyst,0.5ml30%H2O2to40ml acrylic polymerization wastewater and response for2hours.Ce/AC catalyst was characterized by means of BET, then found that rare earth element Cedid bearizing effect.Put Cu, Mn, Fe3kinds of metal respectively mixed with Ce, calcinedunder600℃for4hours to get Cu-Ce/AC, Mn-Ce/AC and Fe-Ce/AC catalyst that the bestratio of metal for Cu:Ce=1:1, Mn:Ce=1:1, Fe:Ce=1:4.Investigate catalyst’s activitythrough continuous reaction and found that fresh load activated carbon catalysts to CODremoval with adsorption in first, with the increase of the number of use, adsorption anddegradation will gradually achieve balance. The catalyst effect and stability of Mn-Ce/AC(Mn: Ce=1:1) is the best and the catalyst continuous used5times that acrylic polymerwastewater’s COD removal rate can remain above75%. However, the wastewater CODremoval rate of the pure activated carbon was only30%after using5times and the activatedcarbon inactive. This suggests that the preparation of catalyst has a certain catalyticpropertiesB/C value of the wastewater from0.20up to0.56or so.Using AASS to measure thedissolubility of the metal ions of catalyst after reaction, found that Cu2+dissolving outseriously, Mn2+Dissolution at least, more stable relatively.At the same time, discoverd thatthe rare earth element Ce has reduced active component dissolution, and enhanced the effectof catalyst activity.Three metals catalysts had also be manufactured.The reaction catalyticefficiency is around60%after three times.There was little difference between them,which notas good as two metal catalysts. Observing the apparent morphology of Fe-Mn-Ce/AC catalystthat after5times used by TEM, found that its surface has carbon deposit,but lower catalyticactivity.